Squat Depth: A Physical Therapist’s Perspective

One of the most debated topics in the weight lifting world is that of squat depth. At most gyms you will see everything from mini-knee bends, to “A*s to Grass” squatting. So how do you know how deep is deep enough?

Anatomy and Biomechanics:

As per usual, let’s cover a quick lesson in anatomy and biomechanics before we dive into the debate.

The classic barbell squat primarily works your gluteal and quadriceps muscle groups. Together with the hamstrings, calves, abductors and adductors, the body works to control the weight as you descend and ascend throughout the lift. Because of its large compound movement the squat it is often considered a full body work out and one of the 3 major lifts (along with deadlifts and bench press).

During the lowering (eccentric) phase of a squat several of your muscles contract as they elongate to control the speed at which you descend. At the hips, the gluteals and hamstrings work to prevent rapid hip flexion. At the knees, the quadriceps serve to slow down the amount of knee bend you have, and at your feet the calf muscles work to control how much dorsiflexion occurs at your ankles. During the upward (concentric) phase of a squat the same muscles are engaged again. This time they activate in the opposite manor, meaning that they shorten as you stand up. The gluteals and hamstrings work to straighten your hips, the quadriceps activate to extend the knees, and the calf muscles work to push into the ground.

In addition to muscular activation and strength, several anatomic factors impact the squat. Core strength, hip mobility and bone structure all dictate your ideal form. You must be able to correctly stabilize the spine as you move through your squat by keeping the low back in a neutral position. This means the low back should be relatively straight and not rounded, curved or arched. Hip mobility plays a key role in achieving lower positions at the bottom of a squat. The amount of rotation throughout your lower leg dictates how wide your stance should be and ankle mobility affects how far down you can move before your heels come off the ground.

Personal Differences: So what do you do?

Your body is the only one that can truly answer the question of how far down you should be squatting. Don’t get too caught up when someone tells you to never go past 90 degrees or to always squat butt to the ground. You should be squatting as low as you can while maintaining a tight core and a neutral back. Once you feel your pelvis tilt backwards and your lower back flatten, you have gone too far. Everyone’s breaking point may be slightly different. For example, individuals with relatively long legs compared to their torso will have a difficult time keeping their weight on their heels, making it harder to go past parallel without rounding the back.

As for those who advocate squatting to the floor, I would caution that you should go as low as your form allows. Studies have found that the quadriceps muscle contracts with high levels of activity at 90 degrees of knee bend. This means that if you are going excessively deep in hopes of working a larger range of motion (ROM), the potential gains might not be much more than stopping at parallel. It certainly means that the risk vs. the reward of squatting lower than your form allows probably isn’t worth it.

You should also be aware that even if your form is perfect, squatting greatly increases the stress and compression placed upon your knees and spine. This is because the nature of the movement redirects force vectors and places your muscles at a mechanical disadvantage, requiring them to overcome forces much greater than the poundage on the bar. Individuals with hip, knee, or low back conditions should place extra consideration into whether or not squatting is the ideal form of strengthening for them.

Bottom Line

Squat as low as your form allows. There is no single correct depth that everyone should be squatting to. Personal factors such as hip mobility and core strength impact the ideal squat depth. If you are unsure how to analyze your squat form than keep a couple things in mind. Throughout the motion you should keep a tight core and maintain a neutral spine position. This means having no curve or bend in the low back. If you feel your hips/pelvis dipping forward or backward you likely have gone too far. If you are reading this in attempt to find a quick guideline for your lifts, without assessment of your technique then I would recommend you squat to 90 degrees of knee bend. This will help prevent form breakdown and avoid placing excessive stress through the low back while still providing you adequate ROM for significant strength gains.

Side Notes:

Common Technique pitfalls while squatting:

Valgus Collapse of the Knees:

Valgus collapse is the inward bending of the knees as if they were moving together into a “knock- kneed” position. This often occurs when the lateral hip muscles are not strong enough to stabilize the weight you are squatting and as a result your knees tip inward while the gluteus medius is overpower. I often see this technical error at the sticking point (or bottom) of a squat right as the person is pushing into the ground to return to the standing position.

Anterior Translation of the Knees:

Translation of the knees over the toes means that your knees are moving too far forward out over your toes as you go into the low position of a squat. This usually occurs when you are not sitting your buttock backward enough or you are placing too much weight through the balls of your feet. Keep your heels on the ground and your weight placed through the back half of your foot throughout your squats.

Overall, you should be putting those gym mirrors to good use. Don’t just admire your biceps in between sets; observe your knees as you go down into the squat. Don’t let them dive inwards or move out past your toes. If you are unable to consistently do this than lower your weight to a resistance level you can.

To learn more on weight lifting and strength training keep an eye out for upcoming articles on the Lake Washington Physical Therapy website.

It is no secret that spinal health can make or break (pun intended) an individual’s overall life quality. I believe if you are investing precious time in the gym you should be doing it safely and in the most efficient way possible. For this reason I set out to answer two questions: Do you need a weight lifting belt, and if so, when should you use it?

Anatomy And Biomechanics:

Before we discuss the concept of a lifting belt you should have a brief understanding of the human body and the biomechanics behind spinal stabilization.

Functionally the human “core” is made up of several muscles that act to stabilize the spine throughout movement. For simplicities sake, we will focus on the group as a whole with an emphasis on the deep core muscles such as the Transversus Abdominis (TA). Attaching to the tissue at the center of your stomach near the belly button, the TA runs down towards your groin and then out and around your back. You can picture it as a corset or a wide belt. When contracted the TA functions to provide stability to the lower segments of your spine by compressing the contents of the abdominal cavity and increasing the tension throughout the muscular fascia that runs along the base of your spine. This is important because as you lift weights you want your spine to sit still, and not slide around under the external force of your work out. If you have weak core musculature than your spine is at an increased risk of excessive curvatures and harmful intervertebral movement.

Similar to other muscles, the Trasnversus Abdominis can be strengthened by actively contracting it. Just as doing bicep curls helps to grow your biceps, abdominal contraction while lifting, moving and during everyday life can help to grow your core strength.

Pro’s And Con’s of the Weight Lifting Belt

The good, The bad, and the strong.

Pro’s Include:

Supplying the core muscles with external assistance in their contraction towards the spine

Providing proprioceptive feedback to the muscles of the core, enhancing their contraction

Preventing excessive spinal curving or arching during a lift

Con’s Include:

Overuse resulting in:

Reduced training of the abdominal musculature that occurs with self-bracing and helps to improve overall core strength

Physical/Mental reliance on an external support system that will not always be accessible in life outside of the gym

Bottom Line

My personal suggestions for who should wear a weight lifting belt, and when they should wear it.

WHO Should use it?

Beginning weight lifters: No.

Novice lifters should focus on technique. You should not be maxing out or performing exercises to fatigue that will result in form breakdown

You have lots to gain from focusing on core stability throughout all workouts, therefore providing your abdominal muscles with the stimulus they need for growth

Moderately experienced lifters: No.(For the most part)

You too have more to gain from focusing on core stability throughout the lift than by belting up for 1 or 2 extra reps

Experienced weight lifters: Yes. (If lifting heavy)

By now you are likely lifting at or near your max and will benefit from the supplemental stability of a belt

You can improve your heavy lifts by focusing more intently on form and specific muscle activation rather than focusing on solid core contraction

WHEN you should use it:

When performing maximal or near maximal lifts for muscle groups that directly impact the spine

Examples: Squats, Dead Lifts, Power Cleans, Snatches

Caveat: Some may benefit from wearing a belt even when performing a lift that does not directly impact the spine, such as while benching (see the side note section below)

When performing lifts for duration where fatigue and form break down are inevitable. Yes, that means you cross fitters!!!

If the WOD has you performing high volume exercises with little rest such as squats and deadlifts you should be wearing a belt. This is because even the most experienced lifters who are conscious of technique will begin to have decreased core contraction and form breakdown with endurance related activities and AMRAP exercises

When advised by your medical professional due to issues with spinal instability

Common Sense!

When you DO NOT need it:

When lifting accessory muscle groups

Simply put, the further away the target muscle is from the center of your body, the less you need a belt

Examples: Training of the biceps, triceps, shoulders and calves

When specifically targeting work outs for the back musculature

The core functions to stabilize your spine, AKA the back. So why not train the entire back and get a core work out while performing those lat pull downs?

Side Notes:

Bench Pressing and Belts:

Some would argue that if you are attempting your max during a bench press you should be utilizing an arched back in order to shorten the bench stroke, decrease the required range of motion and to prevent excessive internal rotation of the shoulders

If you are utilizing this technique, you may benefit from a lifting belt to help stabilize the lower spine as it arches backward toward the bench

No Belt, No Problem:

Individuals lifting heavy weight may reasonably choose to never wear a lifting belt if they have built up enough core strength to properly stabilize the spine throughout their exercise. Many successful Olympic style weightlifters choose to never wear a belt

In Conclusion:

A weight lifting belt serves to stabilize the spine throughout movement by enhancing your core contraction and increasing the pressure around your low back. It does not completely replace the need for active core contraction.

A lifting belt is a tool, and like many tools it can be used or misused. If you are training muscle groups that directly impact your spine at close to maximal weight or high volume, than you should wear a weight lifting belt.

If you aren’t doing either of those, then do yourself a favor and put those precious gym hours to their maximal use. Don’t use a belt, keep your abdominals tight, and get your arms and legs ready for beach season while simultaneously training your core!

To learn more on the core musculature, how to contract/strengthen it, and on topics such as the valsavla maneuver keep an eye out for our upcoming articles.